The present invention relates to a mine roof suppport which has a preferably one part sole plate and a roof shield which may be pivotally subdivided, in which the sole plate and the roof shield are respectively pressed by a plurality of props against the floor and the roof of the mine gallery, and in which means are provided to maintain the position of the props relative to the sole plate and the roof shield.
While many attempts have already been made in the art to satisfy the requirement of maintaining the position of the props relative to the sole plate and the roof shield, none of the known constructions properly counteract the forces tending to shift the roof shield and the sole plate in horizontal direction. These forces resulting from the pressure of the surrounding rock tend to move the roof shield relative to the sole plate in the direction toward, respectively away from the mine face. The thereby resulting stresses in the props and at the pivotal connections thereof to the sole plate, respectively to the roof shield, are high and lead to such damage of the props or the connections thereof, which makes an exchange of the props necessary. This evidently leads to interruption of the operation. Various attempts have already been made to coordinate stabilizing elements with the props to maintain the latter substantially normal to the longitudinal direction of the sole plate and the roof shield, even if relatively great forces try to shift the sole plate and roof shield in longitudinal direction with respect to each other. Such known stabilizing elements are for instance spring packages or direction cylinders which, as a rule, are connected to the sole plate and act on the lower region of the props. Even though the known stabilizing elements are of relatively complicated constructions, they are only to a limited degree able to counteract the shifting forces between the sole plate and the roof shield. The reason for this failure is the usually large lever arm between the sole plate and the roof shield, which prevents with the known stabilizing elements to establish an effective counterforce against the above-mentioned shifting forces.